1. Technical Field
The present invention relates generally to circuit board connectors, and more particularly, to a precision-locking standoff connector for mounting a circuit board with a slit collar.
2. Related Art
Electronic circuit board assembly requires the ability to securely lock a circuit board in place for proper operation. For example, typical personal computer (PC) circuit board operation requires locking the board into position after it, and in particular a chip connected thereto, has been “best-fit” to a copper heatsink or coldplate. The term “best-fit” refers to how the circuit board is coupled to the heatsink via thermal transmission materials in a near-perfectly parallel fashion. Establishing a thin, uniform thermal interface between chip and heatsink is critical for achieving adequate thermal performance for high powered applications. Variable height standoffs are sometimes used to accommodate variations in stack-up height and tilt. Non-parallelism between chip and heatsink will increase a thermal interface gap, thus decreasing thermal performance. Variable position standoffs enable parallel assembly between chip and heatsink while accommodating non-parallelism between circuit card and chassis. Referring to FIG. 1, one conventional approach for locking a circuit board 6 into position is shown. Circuit board 6 includes a chip 8 mounted to a heatsink or coldplate 10 via thermal transmission material. In this approach, as shown in FIG. 2, split expanding plastic standoff connectors 12 are used to mount circuit board 6. Returning to FIG. 1, in this setting, expanding plastic standoff connectors 12 are mounted to a chassis 14 and mounting openings 16 of circuit board 6 are placed over ends 18 of standoff connectors 12. As shown in FIG. 2, as threaded fastener 20 is tightened into end 18 of a standoff connector 12, slit portion 22 of standoff connector 12 expands against an interior of mounting opening 16. A drawback of this type mount is that, as standoff connector 12 expands, it tends to move circuit board 6 vertically and disturb the best-fit alignment of circuit board 6 (i.e., chip 8 thereof) to the heatsink/coldplate 10. For example, slit portion 22 tends to vertically move (with a V-shaped expansion profile) the circuit board 6 rather than simply horizontally clamp it in position.
In view of the foregoing, there is a need in the art for a standoff connector for maintaining a best-fit alignment between a circuit board and heatsink.